ABSTRACT
Objective To isolate neutralizing monoclonal antibodies to Tier 2 viruses in a Chinese patient with HIV-1 infection. Methods Monoclonal antibodies were isolated using single B cell sorting and monoclonal antibody expression technique. The international ImMunoGeneTics database (IMGT) was used to analyze antibody variable region genes. Antibody binding ability and neutralizing activity were tested by enzyme linked immunosorbent assay and TZM-bl/pseudovirus assay,respectively. Results Two monoclonal antibodies (E11 and H2) that could neutralize two Tier 2 viruses were isolated from the patient with clade B HIV-1 infection. Heavy chains of E11 and H2 were derived from IGHV4-4*08 with a somatic mutation rate of 15.79% and 14.74%,respectively. Light chains were both derived from IGKV3-15*01 with a somatic mutation rate of 8.33% and 7.95%, respectively. E11 and H2 could bind to HIV-1 clade B, CRF01_AE and CRF07_BC viruses. The half maximal inhibitory concentration(IC50) values of E11 and H2 were 18.78 μg/ml and 22.43 μg/ml against 398-F1 virus and 43.35 μg/ml and 39.45 μg/ml against 25710 virus. Conclusion In this study, two neutralizing monoclonal antibodies to two Tier 2 viruses were identified in the patient with HIV-1 infection,which might provide reference for the development of AIDS vaccines.